RAT-A-TATS: Joshua Fellows signals victory outside a Manhattan courthouse, but his “victory” was short-lived — he was held on a gun rap. Photo: David McGlynn

The Occupy Wall Street protest was only a temper tantrum away from turning deadly.

An Ohio tattoo artist with a violent past was carrying an unlicensed handgun and 32 rounds of ammo as he drove around the city taking part in Thursday’s “Day of Action’’ protests, the NYPD claimed yesterday.

“He has a temper,” Youngstown, Ohio, Police Capt. David McKnight said of Joshua Fellows, 32, who was charged in Manhattan on Saturday with criminal possession of a weapon.

Fellows was separated from his weapon due to a lucky break.

Cops stopped his truck at 12:30 p.m. because they spotted him driving recklessly at Broadway and Exchange Place as the occupiers tried to disrupt the New York Stock Exchange.

Up to 40 people were jumping in and out of the open back of the moving Budget rental truck, and Fellows had no driver’s license, cops said.

The officers didn’t have time to immediately search the truck, and Fellows, in overalls, a striped shirt and straw hat, initially went free.

Then cops made a frightening discovery. A leather case was wedged between the two front seats. In it was an unloaded .45-caliber gun and enough bullets to kill or injure scores of people.

They began hunting the heavily tattooed hothead, finally tracking him down at 9:10 p.m. Saturday at West Street and Rector Place.

He was arraigned last night on a charge of weapon possession and held in lieu of $25,000 bail.

Fellows had rented the truck in North Carolina — where he had been crashing at the Occupy Asheville encampment — and drove to New York for the protest.

His mom, Chris Fellows of Youngstown, told The Post her son was a staunch Christian committed to the OWS protest — but she admitted he has a short fuse.

“Yes, he does have a temper. But he’s doing what he needs to do,” she said.

Chris Fellows said she didn’t know why her son was carrying a gun but noted that he comes from the south side of Youngstown.

“It’s kind of a tough area. My husband has a gun, too” she explained. “He’s a very nice guy. He does have a temper, but he’s also a nice guy. He would give you the shirt off his back.”

But a November 2009 Youngstown police report on a domestic-violence incident involving Fellows and his ex-wife painted a much different picture.

It said Fellows flew into a rage after his young son “told his dad . . . that he has a temper.”

Fellows, the report said, ran from the house, jumped in his truck and purposely smashed it into his wife’s Volvo before fleeing.

When cops caught up to him, he had a switchblade in his pocket, the report said.

His wife told cops that “Joshua has a bad temper. He has gone into a rage in the past and broken chairs,” the report said.

Chris Fellows said yesterday that her son was familiar with New York’s tough gun laws.

“He’s aware of what he’s gotten himself into,” she said.

Matt Sky, a protest spokesman, said his group does not support “any criminal activity like the actions of Mr. Fellows.’’